Machine for -detecting and ejecting improperly labeled cans



April 10, 1956 M. 1.. BOX ETAL 2,741,365

MACHINE FOR DETECTING AND EJECTING IMPROPERLY LABELED CANS OriginalFiled Nov. 28, 1949 5 Sheets-Sheet l g F'IEE'| l 3 mentors ME RR! L L.BOX

ROEERT W. 0450 April 10, 1956 L, BOX L 2,741,365

MACHINE FOR DETECTING AND EJECTING IMPROPERLY LABELED CANS OriginalFiled Nov. 28, 1949 5 Sheets-Sheet 2 Snventor; HER/'7. L. BOX

ROBERT W. 6450 (Itiorneg April 10, 1956 M. L. BOX ETAL 2,741,365

MACHINE FOR DETECTING AND EJECTING IMFROPEIRLY LABELEZD CANS OriginalFiled Nov. 28, 1949 '5 SheetsSheet 3 I P N o b i v m m 1 Inventors nMERE/L 1.. BOX

HUBER? W. (M5017 Gttorneg April 10, 1956 Box ET AL 2,741,365

MACHINE FOR DETECTING AND EJECTING IMPROPERLY LABELEID CANS OriginalFiled Nov. 28, 1949 5 Sheets-Sheet 4 3m entor HERE/L L. 80X

ROBERT W. 6450!! (Zttorneg April 10, 1956 M. 1.. BOX EI'AL 2,741,365

MACHINE FOR DETECTING AND EJECTING IMPROPERLY LABELED CANS OriginalFiled Nov. 28, 1949 5 Sheets-Sheet 5 m 227 FIE J III v 227 ll 2 '7 dik 5225 5 was 5% w z 3nventors l 3 7 MERE/L L. 50x F I I3 14.- I 8 ROBERT w.64.90

(Ittorneg United States Patent i MACHINE FOR DETECTING AND EJECTIN GEQPROPERLY LAEELED CANS Merrel L. Box, Buena Park, and Robert W. ason',Fullerton, Calif., assignors to Men-e] Manufacturing, Fullerton, Calif.

Original application November 28, 1949, Serial No. 129,706, now PatentNo. 2,660,304, dated November 24, 1953. Divided and this applicationDecember 31, 1952, Serial No. 329,092

12 Claims. (Cl. 299-81) This invention relates to apparatus forinspecting and sorting articles and particularly to an apparatus adaptedfor use in inspecting the labels of cans and capable of separatingdefectively labeled cans from those to which perfect labels have beenproperly applied, the apparatus having particular utility when used forinspecting cans delivered from a can-labeling machine.

The present application is a division of application Serial No. 129,706,now Patent 2,660,304, filed by us November 28, 1949.

Various machines have been proposed for inspecting and sorting canspassing from can-labeling machines, the purpose of such can-sortingmachines being to detect cans which have improperly applied and damagedlabels and to separate such defectively labeled cans from the line ofcans being conveyed from the labeling machines to packaging apparatus.While such sorting machines are employed quite extensively in canneriesand other processing establishments, it is common knowledge that theyare quite inefficient in performing their intended function. Suchinspection machines operate on the principle of electrical detection,that is, they employ one or more detector or contact elements disposedin the path of move ment of the cans rolling from the labeling machineand across which the cans pass. The detector elements are connected inan electrical circuit which includes one or more solenoids capable, whenenergized, of operating a dual gate disposed in the path of movement ofthe cans so as to eject improperly labeled cans from the line of canspassing normally through the machine.

The detector elements are adapted to engage the pen'phery of eachlabeled can and are intended to close the electrical circuit through themetal of the can when they encounter exposed surfaces of the can, thatis, areas of the cylindrical surface of a can which have not beencovered by the label, as may occur when no label has been applied, whenthe label is improperly applied, or when the label is torn. However, ithas been determined that previous can-sorting machines are subject toseveral deficiencies. For example, in such machines a pair of laterallyspaced electrical detector elements are employed and function to closethe gate solenoid when an exposed portion of a can bridges the entiregap between the two elements. It is apparent, therefore, that unlessthe'tear in the label is at least as long as the gap, the electricalcircuit will remain open, and the defective can will not be ejected bythe gate. elements are usually located adjacent the center of the lineof travel of the cans so that they detect only those exposed portions ofa can which appear in the central portion thereof. This is adisadvantage since, as is well known to cannery operators, almost alltears occur adjacent the edges of the labels due to the fact that theseedges sometimes catch on various parts during-the label applyingoperation, and, due to improper feeding and uneven tensioning of thepaper, the detectorelements do not always contact the edges of the can.As a tesult;cans having damaged labels are delivered to the packagingMoreover, the detector or contact 2,741,355 Patented Apr. 10, 1956machine, unless the cans are subsequently inspected by cannery workers.

It often occurs that the paper labels become torn at the overlappingseam, and it is'thus imperative that the detector means engage thisportion of the periphery of a can rolling through the machine. When cansof predetermined diameter are to be sorted, the detector elements are sodisposed that they engage the seam of the label. However, it is highlydesirable that the machine be capable of inspecting cans of variousdiameters. Consequently, it is necessary that the detector elements beeither adjustable lengthwise of the track or be of suflicient length toinsure that they will positively engage the seam portions of labels oncans of different diameters as the cans roll along the track. In oneform of conventional apparatus, the detector means consists of a pair oflaterally spaced, longitudinally extending detector bars upon which thecans roll during their travel along the track, these bars being intendedto contact bare portions of cans to which the labels have beenimproperly applied at the seam. Such detector bars are inefiicient inperforming such function and have the disadvantage of creatingfrictional drag on the cans to impair their free rolling movementthrough the apparatus in which they are incorporated.

Another disadvantage of prior detector means of conventional can-sortingmachines is that they are unable to detect loose flaps of the canlabels. That is to say, it sometimes occurs that during the applying ofa' label, the overlapping end of the label is inadequately glued to theunderlying end of the label with the result that the overlappingendprojects from the can in a loose flap and is quite apt to be torn offduring subsequent handling to m'ar the appearance of the can or to causedisplacement of the entire label from the can. Priorcan-sorting'apparatus embody nomeansfor detecting such loose flaps,

and as a result defectively labeled cans are'often packaged Anotherimportant objectis to provide a detector means which comprises a pairofdetector elements along which the cans travel, said elements beingin theform of relatively long coil springs'eXtending-in the'direction oftravel of the cans. Due to their resilient nature, the detector springsyieldingly engage the peripheries of the cans and thus positivelycontact the same.

Another object isto provide a detector means, of the character referredto above, in which the detector springs are made in the'form of endlesselements carried by longitudinally spaced pulleys, said springs beingrotated in the direction of travel of the cans through the machine sothat the springs oifer little or no resistance to the movement of thecans. 7

Another object is to provide a detector means of the type indicatedin-whichthe individual spring elements are adapted to be so disposedthat they engage the end portions of the cans, where themajor part ofthe defects occur in the labels. A related object is to so connect thedetector elements in the electrical circuit for the gateoperating meansthat closing of the electrical circuit is established through eitherelement, the metal of the can and the track along-which thecan rolls sothat it is possible to detect small tears or other imperfectionsoccurring adjacent the edges of the label. Since the'elements areelongated and their eifective length is at least equal to thecircumference of a can, they positively inspect the entire label forimperfec'tions.

Another object is'to provide detector means of the type specified inwhich endless detector elements are adjustably mounted so that they canbe inclined with respect to the track along which the cans roll. By thisconstruction, the leading ends of the detector elements, that is, theends nearest the end of the track upon which the cans enter 'theapparatus, can be'adjusted vertically so as to cause a predeterminedlength of the elements to be disposed in the path of movement'of' thecans, the efiective length of the elements being adjusted so that it isat least equal 7 to the circumference of the cans being inspected, theaddifierent diameters.

It is another object of this invention to provide a cansorting machinewhich includes a second detector means for detecting the presence ofloose flaps on the can labels, this means consisting of a crystaldetector having a sensitive finger disposed in the path of movement ofthe cans and adjustable longitudinally of the track to adapt it to bepositioned at a location wherein it can be engaged by the justment thusadapting the elements to act uponcans of loose flap of a label. a

Another object is to provide in a machine of the class referred to anelectronic circuit in which the spring-type detectors and the crystaldetector are connected, the circuit also including an electronic controltube which, when activated, functions to actuate a relay, the latterserving to close an electrical circuit which energizes gate-operatingsolenoids, a switch disposed in the path of movement of the cans andadjacent the gates being connected it series in the electrical circuitand-operated by the defec- 7 simple and readily operated.

A still further object of the invention is to provide a can-sortingmachine which is especially simple in construction and one whichfunctions in a more positive manner than other machines heretofor eemployed-for the A same purpose.

Further objects will appear from the following specificationand from thedrawings, which are intended for the purpose of illustration only,-andin which; a

Fig. l is a longitudinal sectional View through the improved can-sortingmachine;

Fig. 2 is a sectional plan view, taken on line 22 of Fig. 1; Fig. 3 is across-sectional view, taken on line, 33 of Fig. 1;. V

Fig. 4 is a cross-sectional view, taken on line 4--4 of Fig. 1;

Fig. 5 is a cross-sectional view, taken on line 55 of Fig.1;

Fig. 6 is a diagram of the electrical circuit of the machine and theelectronic circuit for controlling the opening and closing of theelectrical circuit;

Fig. 7 is a somewhat enlarged longitudinal section similar to Fig. 1 butshowing modified forms of defective label and loose end flap detectordevices;

Fig. 8 is a horizontal section in reduced scale taken on the line 88 ofFig. 7;

Fig. 9 is an enlarged portion of Fig. 8 showing a defectively labeledcan rolling along the label detector track section; a I a Fig. 10 is anenlarged fragmentary plan view of an electrical contact and canpositioning strip mounted on a portion of the can supporting track,portions of a strip supporting bar being broken away;

. tively labeled can to cause the gates to open as the can ap- V tion.

4 r a detector blade looking in the. direction of the arrows 11-11 inFig. 8;

Fig. 12 is a fragmentary section taken on the line 12-12 of Fig. 11;

Fig. l3is an enlarged fragmentary sectiontaken on V Fig. i5 is ahorizontal section taken on the line 15-45 V of Fig. 14; and V r Fig. 16is a fragmentary vertical section taken on the line 16-16 of Fig. 14,the lower support portions shown a in Fig.14'being omitted.

Referring to the drawings in detail, the improved can-sorting machinecomprises a pair of longitudinal side frames 10 and 11 which areprovided on their inner faces with longitudinal ledges 12 and 13 whichto gether provide a track '14 along which cans 'C can roll through themachine. The track 14 may be aligned with a pair of conveyors 15 and 16,the conveyor 15 being adapted to convey labeled cans from a labeling'machine (not shown) while the conveyor 16 transports the cans from thesorting machine to any suitable equip: ment, such as a packaging unit(not shown). The cans, upon being delivered onto the track 14, are fedtherealong in spaced relationship by means to be later described. At apoint substantially midway of its length, the track 14 is interrupted toprovide adischarge opening or' gap 17 through which defectively labeledcans or cans having no labels are ejected from the line of cans passingthrough the machine. 7 a

Gate members 26 and 21 are slidable in guideways 22 and 23 of the sideframes 19 and 11 and are normally projected inwardly by springs 24 and25 to cause their inner ends to align with and form continuations of thetrack, the gates thus normally bridging the gap 17 to prevent cansfrom'falling therethrough during their 'ravel through the machine. Whenthe gate members 2b and 21 are drawn laterally outward, however, a can Cis caused to fall through the dischargeopening 17 into a chute 26 whichconveys it to any suitable loca- The gate members 20 and 21 areadapted'to be withdrawn by means of respective solenoids '29 and 3'!)which, as shown in Fig. 6, are connected in an electrical circuitindicated generally by the reference character 33. A normally openmicroactuated switch 33 is connectedin series in the circuit 31 and isdisposed adjacent the leading edge of thegate'members 2'5) and 21 withits actuat ing' button 36'located in the path of movement of the cansthrough the machine so as to be depressed by a defectively labeled canin the manner to be hereinafter more fully explained. Also connected inseries injthe.

electrical circuit 31 (Fig. 6) is the; switch arm 34 of a relay 35, theswitch arm 34'being normally open.

The side frames 10 and 11 are adapted to be adjusted toward and awayfrom each other so as to vary: the

width of the track 14 and thus adapt the machine to op crate on cans ofdifferent lengths. The adjustment means consists of a pair of adjustingspindles 37 which are rotatable at the ends of a bed plate 3-3. The endportions of each spindle 37 have screw threads'of opposite hand, thethreads turning in the screw-threaded bores of bosses 39 at the endportions of the side frames 16 and 11*(Fig, 2). The spindles carry knobs40"at one end and have The sideframes 10 and 11 are provided withvertical extensions 45 which are connected by longitudinal struts 46.Rotatable in bearings on the extensions 45 are shafts 4 7 and 48, eachshaft carrying a pair of pulleysSll, around which a pair of feedingbelts 51 extend. Carried by the shaft 47 is a grooved pulley 2which isrotated by-a belt 53 surrounding a similar pulley 54 on the drive shaftof an electric motor 55 (Fig. 1). When the motor 55 is operated, thefeeding belts 51*are caused to travel in the direction indicated by thearrows in'Fig. 1. v The belts 51 are adapted to engage the peripheriesof the'cans C delivered by the conveyor 15 onto the track 14 and tocause the cans to roll therealong toward the right as viewed in Fig. l.A roller 57 is rotatable between the structs 46 and its reduced ends areslidable in vertical slots 53 in the struts. Blocks 59 are urgeddownwardly by springs 66 and engage the ends of the roller 57 to depressthe latter into engagement with the inside of the belts 51. In thismanner, the roller 57 serves as a belt tightener and, due to the springaction, it tends to bow the lower portion of the belts 51 downwardly asshown in Fig. l. The roller 57 is disposed above the discharge opening17 so that when a defectively labeled can arrives at this position, theroller, acting against the belts, forcibly ejects the can when the gatemembers 20 and 21 are opened.

As illustrated in Fig. l, the shafts 47 and 48 are rotatable in bearingblocks 62 which are slidable in vertical openings in the extensions 45.The bearing blocks 62 are connected to the lower ends of adjustingscrews 63 so that when the screws are rotated, the pulleys 50 are raisedor lowered to adjust the distance of the lower portion of the belts 51above the track 14 so as to accommodate cans of various diameters.Pivoted on the shaft 47 is a pair of arms 65 which support a cross shaft66 which carries a feeding roller 67. The shaft 66 and the roller67 aredriven from the shaft 47 by means of a belt 68 passing around pulleys 69and 70 carried by' the respective shafts 47 and 66 (Figs. 1 and The arms65 are normally pivoted downwardly by means of a spring 72, thismovement being limited by the engagement of an adjustable stop screw 73on one arm 65 withapad-74 on the forward extension 45. The feedingroller 67 functions to feed the individual cans C onto the track 14 tobe thereafter fed by the belts 51. As each can is fed onto the left-handend of the track 14, the roller 67 engages the same and propels ittoward the right, the roller yielding upwardly to permit the can to passtherebeneath. The rotative speed of the roller 67 is such that the cansare fed toward the right at a predetermined speed, and the roller thusacts to separate the cans and cause them to move along the track inpredetermined spaced relationship.

Rotatable beneath the track 14 adjacent the left-hand end of the machineis a transverse shaft 76 which carries a resilient roller 77, the shaftbeing driven from the shaft 47 by means of a belt 78 passing aroundpulleys 79- and 3% on the respective shafts 47 and 76. The roller 77 isemployed for driving a pair of detector elements 85 and 86, to be nextdescribed.

The detector elements 85 and 86 are in the form of endless coil springswhich extend around grooved pulleys 87 and 88. The pulleys 87 and 38 arerotatable on studs 89 and 9-9, the latter studs being held in the sideframes 1% and 11. The other studs 89 are carried by blocks 91 slidablein vertical slots 92 formed within downward projections of the sideframes 18 and 11. Adjusting screws 94 on the projections engage theblocks 91 and, by turning the screws, the blocks and studs 89 can beadjusted vertically. The left-hand end of each detector element 85 and86 engages the resilient roller 77 (Figs. 1 and 2) so as to be driventhereby in. clockwise direction, in other words, in the same directionas the lower portion of the can-feeding belts 51. Due to the verticaladjustment of the left-hand end of the detector elements 35 and 86, theelements can be inclined with respect to the horizontal track 14, theupper portion of the right-hand end of the elements beingdisposed'slightiy above the track. Thus, any desired length oftheelements-SS and 86 can be made to project above the track 14, thisbeing an important feature of the invention since it permits theprojection of a length which is sufficient to cause the entire peripheryof the cans to contact the detector elements. As shown in Fig. 2, thedetector elements and 36 are adjusted laterally to positions whereinthey engage the cans rolling along the track 14 adjacent the end flangesof the cans. In other words, the detector elements engage the edgeportions of the labels of the cans and this is important since, aspointed out before, a great proportion of the tears or imperfections inthe labels occur at these edge portions.

The contacts or detector elements employed in prior can-sorting machinesoften become ineffectual due to the fact that their surfaces, whichengage the can labels, become coated with the glue or other adhesiveused to bind the labels to the cans. When such a condition prevails, itbecomes impossible to establish electrical contact between the detectorelements and the metal can, and, as a result, improperly labeled cansare not detected. In the present improved machine, such a condition isavoided by constructing the detector elements 85 and 86 in the form ofendless coil springs. As the elements travel around the pulleys 87 and88, their convolutions are caused to open to a slight extent so that afilm of the adhesive extending between such coils is stretched and thusbroken. To further guard against the accumulation of the adhesive agenton the detector elements 55 and 86, we prefer to utilize a pair ofscraper elements 95 (Fig. l) which are located beneath the elements andwhich are engageable with the elements to strip the adhesive therefrom.The scraper elements 95 may be of any suitable construction and are,therefore, not described in detail. The detector elements 35 and 86travel at a slow rate of speed, when compared to the rate of travel ofthe feeding belts 51, and due to their ability to stretch and contract,scufilng of the labels is avoided.

The sorting machine is further provided with a detector device 98 whichis in the form of a crystal detector having a hair-like finger orwhisker 99 having one end engaging the crystal and another end disposedslightly below the track 14. The detector device 93 is carried byastationary element such as a longitudinally extending arm 109 of thebed plate 38. The finger 99 is adapted to be moved to a very slightextent by a loose flap of a can label as the can rolls along the trackso as to disturb the setting of the inner or lower end of the linger onthe crystal for the purpose to be later explained. When the machine isused in connection with a can-labeling machine, the cans are deliveredto the inspecting or sorting machine in the same relative position, thatis, with the seams of their labels contacting the same point on thetrack. Due to this condition, it is possible to detect loose flaps oflabel seams by the use of the single, small finger'99. However, it isimportant that the finger 99 be disposed at the exact point at which theseam first encounters the track 14 in order to be positively engaged bythe loose flap. Since cans of different diameters can be inspected inthe present machine, the point of engagement referred to above may be atvarious locations along the track. For this reason, it is necessary toadjust the detector device $8 along the track 14 to dispose its finger99 in the appropriate position. As shown in Figs. 1 and 2, the detectordevice 98 is adjustable along the arm 1% and can be held in adiustedpositions by a set screw 162. it is within the concept of the inventionto provide a plurality of the detector devices 98, and in this case thedevices may be adjustable with respect to one another.

The detector elements 85 and 36, and the detector device 98, areconnected in'an electronic circuit, indicated generally at 119, thiscircuit including a rectifier stage 111, and a voltage regulator stage112. The electronic circuit 110 also includes a gas filled control tube113' which is of the type known as a tetrodethyratron' 7 tion on themounting pin.

' of accurate adjustments.

tube and which has a filament 114, a grid llS. and a 'plate'llG;Negative current is'supplied'to the grid 115.

through a'circ'uit line 117 in which the detectorelements 85 and 86 andthe detector device 98 are connected. A line 113 is connected betweenthe'line 117 and the track a normally closed switch 122. The switch 122is preferably of the mic'roactuated type and is positioned to be engagedby the gate 21 when the latter. is retracted bythe solenoid 3t). V

Figs. 7 to 16, inclusive, illustrate a modified form of detector tracl;and loose flap detector. The remaining x 'parts of the apparatus shownin the latter figures however, are generally similar to those shown inFigs. 1

' to 6, inclusive, and will, therefore,"bc designated by the samenumerals employed in connection with 'Figs. 1 to 6, inclusive, with theexception that the sutrix "a'" will be added thereto.

In the modified form of the invention shown'in Figs.

7 to 16, inclusive, the coil spring belt detector elements 85 and 86shown in Figs. 1 to 6, inclusive, are replaced by a pair of pivotallymounted spring biased detector blades 2th) and 20E (Figs. 7, 8, 11 and12). These blades is thin, but not sharp, so that it will cut throughaccumulations of gummy substance which. may overlie the I metalof thecan, but will not cut the label or the metal Since both detector bladesand their of the can itself. mountings are similar to each other, onlythe blade 200 will be described in detail. Each detector blade isreinforced by a stiffening strip 292 secured alongits lower edge. a a

The leading end of each detector blade is pivotally connected to amounting block 2&3 by a shouldered screw arm-guns l are of relativelythin, electrically conductive material, and each is tapered toward itsstraight upper edge, which by a set screw.

tically adjusted position on the second mounting pin 217 Verticaladjustment of the forward end of each detector blade on its firstmounting pin 207 changes the efiective length of the upper edge of thedetector blade which is thereby raised above or lowered beneath the cansup-. porting level oi the track'14q into or. out of can-contacting 1position, as the case may be. The spring biased or normal height of therearward or discharge end of each detector blade, as well as the springpressure exerted thereon by the coil spring 220,.may be adjustedbychanging the position of the spring supporting collar222 on itssupporting pin 217. As in the case of 'thespring belt detectors 85 and86 shown in Figs. 1 to 6 inclusive, the detector blades 290 and 201 areswung downwardly about their pivotal mountings as each can rollsacrossthem, so that when properly spaced from the can ahead, each can wardlyabout their forward mounting pivot pins 204} maintaining the blades freefrom contact :with the second can until the first can has passed beyondthe detector blades, the ejector actuating switch lever 36a and onto thegate or bridge fiangesZiia and 21a.

The properly labeled leading can then would not be deflected downwardlythrough the discharge opening even though the improperly labeledfollowing can should thereupon close the detector circuit, since thesolenoids 29a 204, and is insulated from the screw and from the track14a by an insulating bushing 205. The blade mounting block 293 issecured for vertical adjustment to the under side of the track l ia byamounting pin 207 which is slidably inserted in a hole in the mountingblock. A set screw 208 secures the block in vertically adjusted posi-The upper end of the mounting pin 207 is brazed to one end of a link 289(Figs. 11 and 13), the other end of the link being secured to the underside of the track 14a by a screw 210. Upon loosening the screw 210 and'can be turned without completely loosening the set screw 208 andmounting screw 219 which facilitates the making A second mounting blockmounting block 263 thereon. Screws 212 secure the second block 211 tothe blade, and insulating bushings 213 and a strip 214 of insulatingmaterial insulate the second block 231 from the blade. An endwiseopening notch 215 is provided vertically through each rearward mountingblock 211, and receives freely a second mounting pin 217. which isgenerally similar to, but somewhat longer than, the first mounting pin207. The upper end of this second mounting pin is adjustably secured tothe under side of the track 14:: by a link 218 and screw 219,

and the lower end of the second pin 217 is squared, all

similarly tothe first'pin 207., A blade-supporting coil spring 220 isheld in compression between a washer 221, which rests against the underside of the second mounting block 211, and a collar 222, which issecured in ver- 211 is rigidly secured to each detectorblade rearwardlyfrom the first pivotal and 39a would not be energized until the secondcan had depressed the ejector actuating button'36a. By that time theleading or properly labeled'can of the pair would be almost across thegap, and would be traveling atsuch high speed that it would easily passonto the portion of the track beyond the gap. However, the closing ofthe detector circuit by the defectively labeled second can will cause itto be rejected in a usual mannerby the energizing of the solenoids 29aand 30a.

While such rim-torim positioning of cans passing through the detectorstage of the device is undesirable, and'in fact is impossible if thefeeding or spacing roller 67a of theniachine is in position to contactand properly space the cans, occasionally when extremely high speedoperation is required an inexperienced operator may move the spacingroller 67a upwardly out of the path of the cans,'thereby allowing thecans to pass through the apparatus in rim-to-rim contact with eachother. While it is clear that the detecting sensitivity of the machinewill not be as great with the cans passing through i moving the detectorblades laterally toward or away from the tracks is of great assistancein adjusting the sensitivity of the machine. For example, canners attimes do not wish cans with labels only slightly misplaced or torn onlyat the; edges to be rejected, while at other times they may require thatonly perfectly labeled cans shall be permitted to pass'through themachine. In Figure 9 where a can is shown with its label misplacedendwise of the .can,-it will be noted that the right hand detector blade20!) is positioned to engage an unlabeled or bright portion of the can,and thereby will cause the can to be rejected. By adjusting the detectorblade 2% inwardly further away from its supporting track 14a it isobvious that such cans could be permitted to pass through the themachine in exactly aligned position, and to provide a wiping electricalcontact with the ends of the cans to insure grounding the cans to oneside of the detector circuit while they are passing through thedetecting stage of the device, a spring pressed end contact strip 223(Figs. 7, 8 and 10) is resiliently supported 'on a bar 224 secured onthe upper edge of the side wall of the track 14a by screws 225'. The endcontact strip 223' has a plurality of posts 227 brazed thereto to extendlaterally outwardly through holes 228 transversely through the mountingbar 224.

The end contacting strip 223 is biasedinwardly toward the center of thespace between the tracks by light coil springs 229 surrounding the posts227 and inserted in enlarged inner portions of the holes 228. Thesprings 229 are held in compression between the end contacting strip 223and the bottoms of the enlarged portions of the holes 228 to exert aninward bias on the strip 223. The inward limit of movement of the posts227 under the impulse of the springs 229 is determined by washers 230held in position on the posts. 227 by cotter pins 231 (Fig. 10). Theleading or forward end of the strip 223 and its mounting bar 224 aredisposed at an angle outwardly away from the can supporting track 14a tohave cam-like initial engagement with the ends of the cans as they rollalong the track.

A modified form of loose end fiap' detector 232 is shown in Figs. 14, 15and 16. The flap detector comprises an upright body member 233 ofinsulatingmaterial such as plastic block, supported for verticaladjustment upon threaded rods 234, the upper ends of which are screwedinto threaded holes in the body member 233. The lower ends of thesupport rods 234 are inserted through holes in the laterally extendingend portions of a supporting bar 235, and are secured therein invertically adjusted position by nuts 237 and 238.

The bar 235 is mounted on a transversely extending square rod 239, beingsecured in laterally adjusted position thereon by a U-shaped clamp 240which is drawn into clamping engagement with the rod 239 by screws 241(Fig. 14). The square rod 239 itself is slidably mounted on rods 242(Figs. 7 and 8) which are mounted lengthwise of the machine to the bedplate 38a; The square transverse rod 239 has holes through its ends forslidably receiving the longitudinally disposed rods 242, and is securedin adjusted position thereon by set screws 246 (Fig. 8).

A light, thin, flap-contacting metal strip 243 is mounted with adequateside clearance in a groove 244 extending lengthwise of the top of theinsulative body block 233. The flap contacting strip 243 has a pair. ofvertically slotted holes 245 therethrough, in which are inserted smallretaining bolts 247 mounted-in holes through the insulative block 233.The block 233 is mounted beyond the path of the cans rolling along thetracks, and may be adjusted by means of the nuts 237 and 238 so that theedge of the flap contacting strip 243 is beyond the path of the cans,but is within range of loose label end flaps which may project from acan rolling along the track. While shown as mounted beneath the path ofthe cans it is obvious thatthe detector could be mounted in the samerelative position above the track 14a and just beyond the path of thecans through the machine so that the flap contacting strip 243 would bewithin striking distanceof a loose label end flap. When mounted ininverted position above the path of the cans the weight of the strip243will hold it at its outward limit of movement in the groove 244.-

When mounted upright as shown in the drawings however, a pair ofextremely light coil springs 248 are inserted in holes 249 extendingvertically-through the block 233, the upper ends of the springsprojectinginto the strip receiving groove 244 in the block. Thesesprings are held in compression between the bottom of the'flapcontacting strip 243' and set screws 250" screwed'into the threadedlower portion of each of the springreceiving holes. Each of the setscrews 250 is engaged by 'one'e'nd of a conductor 251 the other end of'which is connected to one of the vertical threaded block supporting rods234 by a nut 252, thereby to ground the flap contacting strip 243 to theframe of the machine through the light coil springs 248, the set screws250, the conductor 251, the square transverse rod 239 and thelongitudinally disposed rods 242. The strip supporting coil springs 248are of just suificient strength normally to bias the light flapcontacting strip upwardly so that the lower marginal edges of theslotted holes 245 are held in contact with the small retaining bolts247. The springs 248 are so light that they permit the flap contactingstrip 243 to be depressed by the lightest possible touch; namely bybeing rushed by the loose end flap of a label which may projectoutwardly from a can rolling through the apparatus on the tracks 14a.

Contact posts 253 are provided one at each end of the insulative block233, being inserted upwardly through vertical holes provided in the bodyof the block. The contact posts are screwed through threaded holes in apair of metal inserts 254 which are molded integrally in the body of theblock 233. The metal inserts 254 are electrically connected to eachother by a strip 255 of electrically conductive metal secured to theinserts 254 by screws 257. A conductor wire 258 is connected by a screw25? to the connecting strip 255, and thence into the ejector actuatingcircuitv in the same manner as is shown for the loose flap detector 98shown in Figs. 1, 2, 4 and 6. The sensitivity of the loose flap detector232 may be varied in an obvious manner by changing the pressure on thesprings 2481231 means of the set screws 250, and by varying thedistances between the upper ends of the contact posts 253 and the flapcontacting strip 243.

The location of the loose flap detector 232 lengthwise'of the machineshould be such that as the cans from the labeling machine roll along thetracks 14a through the machine the overlapping ends of each label willtend to be on the under side of the can, substantially midway of theeffective length of the loose flap contacting strip 243. It is obviousthat due to the much greater effective length of this latter type ofloose flap detector, than that shown in Figs. 1, 2 and 4, considerableleeway is provided as to where the loose flap can be positioned in orderto actuate the detector element. This is an important factor, since whenthe" cans are fed at high speed through a labeler and thence through thepresent detecting and rejecting mechanism, there frequently is someslippage of the cans which varies the position of the label overlap onsuccessive cans.

The improved can-so'rtin' apparatus shown in Figs. 1 to 6 inclusive,operates'inthe following manner.

The apparatus is prepared for operation by first adjusting the sideframes 19 and 11 toward or away from each other in accordance with thelength of the cans to be inspected, it being noted that the end flangesof the cans are intended to roll upon the track ledges 12 and 13 asshown in Fig. 2. The feeding belts 51 are then adjusted vertically withrespect to the track 14 in accordance with the diameter of the cansto beinspected. after which the height of the feeding roller 67 is alsoadjusted; The inclination of the detector elements and S6 a'n'd thelongitudinal location of the finger 99 of the detector device 93 arefinally adjusted in accordance with the characteristics of the cans tobeinspected.

With the various adjustments thus made; the machine is ready foroperation and the motor 55 is started in a usual manner to cause thefeeding roller 67, the feed ing belts 51 and the detector elements 85and 86 to rotate in directions which will cause cans Cfed onto thelefthand end of the track 14 to be'rolled through the machine along thetrack. During the operation of the machine, the roller 67 acts tomaintain the cans spaced apart at a predetermined distance, thisrelationship not being shown in Fig. 1 since the cans are shown indifferent selected positions for the purpose of illustration. The cans Center the apparatus from a can-labeling machine and, assuming that thelabels have been properly applied thereto, and the labels are notdefective upon entering "the. apparatus, they will be fed therethroughby the belts 51 along the track 14 and delivered'to the conveying means16 whichmay convey the cans to a packaging machine or other equipment. VV

Occasionally a label is defective [or isirnproperly applied and, whensuch is the case, the-can having such a label is separated from the lineof cans. passing through the apparatus in the manner next explained.When a can; having a torn' label rolls along the detector elements 85and 86, the exposed portion of the periphery of the can contacts one orboth of the detector elements, de-

, pending upon the extent of the tear, and since the negative wire 117is connected to the elements 35 and 86 and the positive wire.118 isconnected to the track 14, a short circuit is created which causespositive voltage to flow to the grid 115 of the control tube 113 tocause sufiicient voltage in the line 120 to energize the relay 35.

Closing of the relay switch 34 partially closes the electrical circuit31 in which the solenoids 29 and 30 are connected' his a characteristicof the tetrode thyratron tube'113 that once the flow of sufiicientcurrent to the plate 116 is'established, such flow will be maintaineduntil disrupted by openingthe electronic circuit, for example, byopening the switch 122. e p 7 7 As the defectively labeled can rollsfrom the righthand end of the detector elements 85 and 86, it depressesthe button 36 of the switch 33 so as to close the same. The'circuit 31is thus entirely closed so that the solenoids 29 and 30 are energized toretract the gate members 20 and 21 from the opening 17. Consequently,the defectively labeled can falls through the opening 17 into the.control tube113 to restore it to its original condition.

Opening of the switch 34, of course, opens the circuit 31 to deenergizethe solenoids 29 and 39 so that the gate members 29 and 21 are returnedto the operative position shown in Fig. 3 to. form part of the, track14.

It also occurs that the ends of labels applied to a can are not properlyglued together, and this results 'in a loose flap which projects fromthe periphery of the can. When such a'can enters the apparatus, theloose flap encounters the finger 99 of the crystal detector device 9%and even though the engagement is extremely light, the setting ofthe'inner end of the finger on the crystal is disturbed, thusmomentarily, at least, changing the polarity of the electrical currentin the grid line 117. Such a condition results inactivation or thecontrol tube 113 to energize the relay '35 so as to close the switch 34.When the switch 33 is later closed by the improperly labeled can asthelatter rolls thereacross, the solenoids 29 and 30 are energized'toretract the gate members '20 and 21 to discharge the can from the track14. It is thus seen that the present apparatus functions to detect thepresence of cans having torn or otherwise imperfect labelsand ,cans inwhich the ends of the labels have been improperly joined; and todischarge such cans from thelinc of cans rolling along the track. Itwill also be obscrved that the detector means are extremely sensitiveand positive The operation of the modified form of the invention 7 shownin Figs.-7 to 16, inclusive, will be obvious from :the' foregoingdescription of the, operation of the form thereof shown in Figs; 1 to 6inclusive, with the possible exception of the lateral adjustment of thedetector blades 200 and 201 by means of the links 299 and 218. .To

, accomplish such adjustment, the distance from the end of thercanbeyond which it is desired label defects shall cause rejection mustfirst be setby the canner or customer for whom the cans are to belabeled. This being established, the detector blades 200 and 201 areadjusted at the distance inwardly from the sides ofthe tracks 14a byslightly loosening the set screws'208'and mounting screws 210 and 219(Figs. ll and 12) and, by means of a wrench if desired, turning thefirst and second mounting pins 207 and 217. to swing the links toposition the detector blades at the required distance from, and parallelto the tracks 14a. With the blades'thus adjusted, the

loosened set'screws and mounting screws again are tightened to securethe blades in their newly adjusted positions.

While we have herein shown and described the improved can-sortingapparatus as embodied in a preferred form of construction, by way ofexample, and modified forms of defective label detectors therefor, itwill be I comprising a track along which'the cans roll on their rimsthrough the apparatus, electrically operated means adapted whenenergized to eject a can from said track, an

endless flexible detector element'of electrically conductive materialmounted for continuous rotation in the path and direction of movement ofthe cans along said-track, said detector being adapted to engage theentire periphery of a can moving along said track so as to directlycontact a bare surface of an unlabeled or improperly labeled can,

and a normally open electrical circuit interconnecting said track, saidcan ejecting means, and said endless detector element, said circuitbeing adapted to be closed by contact of said endless detectorelementwitha bare area of a can.

2. A sorting apparatus for detecting and ejecting unlabeled andimproperly labeled cans from a line of cans comprising a track alongwhich the cans rollon their rims through the apparatus; electricallyoperated means adapted .when energized to eject a can from said track;

an'cndless. flexible detector element of electrically conductivematerial extending along said track and mounted for continuous rotationin the path of movement of the cans along said track, said detectorbeing adapted to en gage the entire periphery of a can moving'along saidtrack so as todirectly contact a bare surface of an unlabeled orimproperly labeled can; drive means including a resilient rollerfrictionally, contacting said endless detector element for rotating saiddetector element; and a normally open electrical circuitinter-connecting said track, said can ejecting'means, and said endlessdetector element, said circuit being adapted to be closed by contact ofsaid endless detector element with a bare area of a can.

3. A sorting apparatus for detecting and ejecting un labeled andimproperly'labeled cans from a line of cans,

comprising a track along which the cans roll through the apparatus, saidtrack having a can discharge gap therein, a movable gatenor'mallyspanning said gap and across which the cans roll, electrical operatingmeans electrically connected in a normally open electrical circuit" andadapted upon energization of said circuit to move said gate means in adirection to open said gap to allow a defectively labeled canto falltherethrough,'pulleys spaced longitudinally of said track, an endlessdetector element of electrically conductive material, adapted topartially close said circuit through said track when said traclc andsaid element are'contacted by the exposedmetallic surface. of adefective can, said endless dct0f element being inthe form of an endlesscontinuously moving belttrained around said pulleys and extending alongsaid track and having a portion extending into thepathof the cans moving therealong, and switch means extending into-the path of thedefective can for actuation by the can to complete the closing of saidcircuit to energize said gate operating means and open said dischargegap.

4. A sorting apparatus for detecting and ejecting unlabeled andimproperly labeled cans from a line of cans comprising a track alongwhich the cans roll through the apparatus, said track having a candischarge gap therein, movable gate means normally spanning said gap andacross which the cans roll, electrical operating means electricallyconnected in a normally open circuit and adapted upon closing of saidcircuit to move said gate means in a direction to open said gap to allowa defectively labeled can to fall therethrough, an endless flexibledetector element of electrically conductive material extending alongsaid track and having a portion continuously movable into the path ofmovement of the cans on said track, said detector element portion beingadapted to engage the entire periphery of a can moving along said trackso as to directly contact a bare surface of an unlabeled or improperlylabeled can, whereby to partially close said normally open circuit, andswitch means extending into the path of the defective can for actuationthereby to complete the closing of said circuit.

5. An apparatus as defined in claim 4 in which said gate means comprisesat least one plate-like element slidable in a path extendingtransversely of said track.

6. An apparatus as defined in claim 4 in which said gate means comprisesat least one plate-like element slidable in a path extendingtransversely of said track, said gate operating means comprising asolenoid operatively connected to said gate.

7. A sorting apparatus for detecting and ejecting unlabeled andimproperly labeled cans from a line of cans comprising a track alongwhich the cans roll through the apparatus, said track having a candischarge gap therein, movable gate means normally spanning said gap andacross which the cans roll, electrical operating means electricallyconnected in a normally open circuit and adapted upon closing of saidcircuit to move said gate means in a direction to open said gap to allowa defectively labeled can to fall therethrough, an elongated belt-likedetector element of electrically conductive material extending alongsaid track, said detector element being pivotally mounted near itsleading end and having a portion of its upper run adjacent the leadingend extending into the path of movement of a can moving along the track,means for continuously moving said belt-like detector element upwardlytoward the path of movement of the can and forwardly in the direction ofsaid path, means for adjustably pivoting said detector to vary thelength of the upper run portion extending into the path of movement ofthe cans, said detector element being arranged to engage the entireperiphery of a can moving along said track so as to directly contact abare surface of an unlabeled or improperly labeled can, whereby topartially close said normally open circuit, and switch means extendinginto the path of the defective can for actuation thereby to complete theclosing of said circuit.

8. An apparatus as defined in claim 7 in which said detector elementincludes a pair of endless coil springs arranged in laterally spacedrelation in position to contact the exposed surface of a can adjacentboth beaded flanges thereof, and means for adjusting said coil springdetector elements toward and away from each other in accordance with thelength of cans to be sorted to maintain the positions of said coilspring detector elements relai4 tive to the beaded flanges of cansmoving, through said apparatus.

9.. A sorting apparatus fo detecting and ejecting unlabeled andimproperly labeled cans from a line of cans comprising a track alongwhich the cans rollthroughthe apparatus, said track having a candischarge gap therein, a movable gate normally spanning said gap andacross which the cans roll, electrical operating means electricallyconnected in a normally open electrical circuit and adapted uponenergization of said circuit to move said gate means in a direction toopen said gap to permit a defectively labeled can to fall therethrough,a belt-like endless detector element of electrically conductive materialextending along said track with a portion of the length of said elementdisposed in the path of cans moving along said track, means mountingsaid detector element for adjustable movement relative to the path ofthe cans to vary the elfective length of the portion extending into thepath, said detector element being adapted to partially close saidnormally open circuit through said track when said track and saidelement are simultaneously contacted by the exposed metallic surface ofa defective can, and switch means connected in said circuit andextending into the path of movement of said defective can on said trackto be actuated by said can for completing the closing of said circuit toenergize said gate moving means to open said discharge gap.

10. A sorting apparatus for detecting and ejecting unlabeled andimproperly labeled cans from a line of cans comprising a pair of spacedsupport members affording a track along which the cans roll in spanningrelation, said track having a can discharge gap therein, a movable gatenormally spanning said gap and across which properly labeled cans roll,a normally open electrical circuit means having means therein forwithdrawing said gate from said gap to discharge unlabeled andimproperly labeled cans therethrough when said circuit is closed, anendless coil spring detector element of electrically conductive materialextending along the path of movement of cans on said track and into saidpath, said detector element having a length at least equal to thecircumferential dimension of the can, electrical means connected to saidcircuit and energized by the metallic surface of a can contacting saiddetector element for partially closing said circuit, and switch meansextending into the path of movement of the defective can on said trackto be actuated by said can to complete the closing of said circuit toenergize said gate withdrawing means.

11. A sorting apparatus for detecting and ejecting unlabeled andimproperly labeled cans from a line of cans comprising a pair of spacedsupport members affording a track along which the cans roll in spanningrelation, said track having a can discharge gap therein, a movable gatenormally spanning said gap and across which properly labeled cans roll,a normally open electrical circuit means having means therein forwithdrawing said gate from said gap to discharge unlabeled andimproperly labeled cans therethrough when said circuit is closed, anendless coil spring detector element of electrically conductive materialextending along the path of movement of cans on said track and into saidpath, said detector element having a length at least equal to thecircumferential dimension of the can, electrical means connected to saidcircuit and energized by the metallic surface of a can contacting saiddetector element for partially closing said circuit, switch meansextending into the path of movement of the defective can on said trackto be actuated by said can to complete the closing of said circuit toenergize said gate withdrawing means, feeding means for feeding the cansalong said track in equally spaced relationship, a roller disposed abovesaid track ahead of said feeding means and ahead of said discharge gapand arranged to engage the periphery of cans placed on said track, andoperating means for rotating said roller in a direction to feed cans 7References Cited in the file of this patent UNITED STATES PATENTS 101,217,092 Hopp Feb. 20, 1917 Pigeon Feb. 28, 1922 Wild Oct. 7, 1924.-Poole Nov.; 6, 1928 Flint Jan. 20, 1942 Palmer July 17, 1951 Todd Oct.9, 1951 Goodban June 24, 1952 Venne s Mar. 22, 1955

